User-level performance of channel-aware scheduling algorithms in wireless data networks

Abstract

C e n t r u m v o o r W i s k u n d e e n I n f o r m a t i c a PNA Probability, Networks and Algorithms Probability, Networks and AlgorithmsUser-level performance of channel-aware scheduling algorithms in wireless data networks Channel-aware scheduling strategies, such as the Proportional Fair algorithm for the CDMA 1xEV-DO system, provide an effective mechanism for improving throughput performance in wireless data networks by exploiting channel fluctuations. The performance of channel-aware scheduling algorithms has mostly been explored at the packet level for a static user population, often assuming infinite backlogs. In the present paper, we focus on the performance at the flow level in a dynamic setting with random finite-size service demands. We show that in certain cases the user-level performance may be evaluated by means of a multi-class Processor-Sharing model where the total service rate varies with the total number of users. The latter model provides explicit formulas for the distribution of the number of active users of the various classes, the mean response times, the blocking probabilities, and the mean throughput. In addition we show that, in the presence of channel variations, greedy, myopic strategies which maximize throughput in a static scenario, may result in sub-optimal throughput performance for a dynamic user configuration and cause potential instability effects.

Coordinated load balancing, handoff/cell-site selection, and scheduling in multi-cell packet data systems

“…The aggregate throughput becomes smaller given a larger α. 7 Below we will see that the above feature derives the MAC-layer cell breathing given multiple neighboring cells.…”

“…Recently much attention has been devoted to opportunistic downlink scheduling algorithms [1,2,3,4,5,6,7] that exploit the asynchronous peaks of fading channels of multiple Mobile Stations (MSs) in a single cell. A time-slotted downlink shared data channel, together with the associated signaling and control channels, supports those MSs for the highspeed downlink packet access.…”

“…The other is the High Speed Data Packet Access (HSDPA) which is based on the WCDMA systems [10]. In those systems, the proposed scheduling algorithms work independently in individual cells given certain constraints on long-term intra-cell resource sharing [2,3,5,7] or minimum rate (minRate) requirements [4,6] of MSs. However, to our best knowledge, few studies (see [11] and references therein) are devoted to such systems in a multi-cell environment, where inter-cell interference and asymmetric traffic arrival may be the major hinderance to good resource utilization and high system scalability.…”

Scheduler design for traffic classification in CDMA2000 1xEVDO network

“…For these algorithms, decision metric consists of two parts. One part is highly dependent on channel conditions and the other part has fixed QoS related parameter [2]. One very famous scheduling method used in CDMA2000 1xEVDO network is proportional fairness (PF) scheduling method [3].…”

Adaptive QoS scheduling in wireless cellular networks

“…Obviously, there is a trade-off between providing QoS guarantee and optimizing throughput. Many efforts have been accomplished in the literature before and several approaches have been developed which provide some QoS while still achieving a reasonable throughput [16][17][18]. However, adaptively compromising this trade-off has been also the challenging subject of some efforts in the literature and some approaches have been proposed which tune the trade-off in an adaptive manner.…”